1. Field of the Invention
The present invention relates to memory circuits, and more particularly to a storage element permitting a defined number of write cycles.
2. Description of Related Art
Conventional OTP type (One-Time-Programmable) storage elements allow a single memory write operation. Such circuits can be realized by EPROM (Electrically Programmable Read Only Memory) memories.
In some applications, it would be desirable to use FTP (Few Times Programmable) storage elements (i.e., storage elements allowing a successive and defined number of erasure and rewrite cycles). Conventionally, such FTP storage elements are realized with EEPROM (Electrically Erasable Programmable Read Only Memory) memories or FLASH memories, which are unfortunately expensive because of their complex dual polysilicon technology. For this reason, use of such memories is traditionally reserved for very specific applications.
However, in many applications, even applications that do not justify the high implementation cost of EEPROM or FLASH technology, it would be desirable to benefit from FTP (Few Times Programmable) functionality.